The present invention relates to the control of fungal infection of plants using bacteria, in particular an actinomycete, that is antagonistic to, or produces a material(s) antagonistic to, the undesired fungi.
The loss of crops due to fungal infections is, in the aggregate, in the billions of dollars annually. Fungal infections can harm or destroy either the seed or the growing plant or both. To control or combat fungal infections a number of chemical compounds have been developed through extensive research. These chemical compounds are manufactured in chemical plants and then typically applied to the plants by spraying onto the plants in solution form.
The present invention is directed to a method of achieving fungal control by organisms and/or chemicals which are generated at the site of the plant--in the soil where the plant grows, using an actinomycete as a component to achieve the desired result.
Actinomycetes, such as organisms in the genus Streptomyces have been noted in the past as having antifungal effects. For example, Staib et al. in Mycopathologia, Vol. 70, 1:9-12, 1980 note that one strain of Streptomyces griseus, isolated from the roots of soil potted African violets, had an inhibitory effect against a number of fungi, including Aspergillus niger. De et al. in Current Science, p. 590, 1978 disclose the isolation of a soil streptomycete having broad antifungal activity against a number of fungi including phytopathogens and dermatophytes.
It also has been disclosed that the addition of chitin to soil results in an increase in the production of actinomycetes, Peterson et al. "The Influences of Chitin and Myxobacters on Numbers of Actinomycetes in Soil" Canadian Journal of Microbiology, Vol. 11, pp. 595-596, 1965. In some instances the chitin addition to soil has been reported as favorable toward control of plant diseases, but in the Peterson et al. report the chitin addition favored, rather than helped control, the spread of a Fusarium species of fungus.
Chitin is a white or colorless amorphous polysaccharide that forms part of the hard outer covering or internal layers of insects, crustaceans, and some other invertebrates.